Sorption behavior and crystallinity of jute fiber at higher alkali treatments

Moisture regain of jute fiber was studied at different alkali concentrations and temperatures. It was found that the moisture regain increased up to 4.5N alkali treatment and then leveled off. Variation in swelling temperature had no significant effect on moisture regain. Amorphous fraction calculated from Valentine's equation using sorption ratio was compared with infrared crystallinity. The accessibility was increased with decreasing crystallinity in alkali-treated jute fiber, where as in cyanoethylated jute fiber it increased with increasing the degree of cyanoethylation.     

Subcritical growth of long cracks in heterogeneous ceramics

This paper models the subcritical growth of long cracks in ceramic structures containing heterogeneities. In such cases, the microstructure is believed to promote deflection of the crack. Due to this, the following effects are observed: (i) there is scatter in the K _I-V data; (ii) N, the subcritical crack growth susceptibility coefficient, as obtained from specimens with long cracks, erroneously shows large values as compared to specimens with small flaws; and (iii) the lifetimes predicted from long-crack experiments (especially in the double torsion load relaxation mode) are more than the predictions from short cracks. All of the effects mentioned above are explained by the present model.     

Identification of t' Phase in ZrO2-7.5 wt% Y2O3 Thermal-Barrier Coatings

The presence of nontransformable tetragonal (t') phase in plasma-sprayed ZrO₂-Y₂O₃ coatings enhances the stability of the coating during high-temperature exposure. In this paper, we describe the importance and procedure for correctly identifying t'phase in X-ray diffraction patterns of the as-sprayed and heat-treated coatings. The results agree with the phase diagram. We also point out that in the heat-treated materials, the durability should be specified in terms of t'-ZrO₂.     

Fracture surface energy determination in {1 1 0} planes in silicon by the double torsion method

The fracture surface energy of {110} planes of silicon were determined by the double torsion method on thin samples. Elastic anisotropy was taken into account in the calculations. The determined value of 1.81 J m^?2 compared well with other data in the literature.     

P---T---X behaviour of refrigerant-absorbent pairs

New refrigerant-absorbent combinations for use in vapour absorption refrigeration systems have been investigated. Experimental (P---T---X) data of N---N dimethyl acetamide-R12, cyclohexanone-R12, N---N dimethyl acetamide-R22 and cyclohexanone-R22 combinations have been collected. Data have been presented in usable graphical form and deviations from Raoults law have been calculated. Combinations N---N dimethyl acetamide-R22 and cyclohexanone-R22 are identified as suitable for vapour absorption refrigeration on the basis of solubility criteria.     

Direct detection and isolation of plasmid-bearing virulent serotypes of Yersinia enterocolitica from various foods

A procedure was developed for direct detection, isolation, and maintenance of plasmid-bearing virulent serotypes of Yersinia enterocolitica from different food sources. Plasmid-bearing virulent strains of Y. enterocolitica representing five serotypes were simultaneously detected and isolated from enriched swab samples of artificially contaminated pork chops, ground pork, cheese, and zucchini, using Congo red binding and low-calcium-response tests. The method was also effective in isolating plasmid-bearing virulent strains of Y. enterocolitica from naturally contaminated porcine tongues. Virulence of the strains isolated from these foods was confirmed by PCR, the expression of plasmid-associated phenotypes, and mouse pathogenicity.     

Wear in cylinder liners

Over the years, investigators have extensively studied various aspects of wear in cylinder liners but a survey of the literature has revealed little information on the subject of high wear rates found in the upper portion of the liners. In order to provide a better understanding of the subject, an attempt is made in this paper to assess the primary factors responsible for the high wear rates. It is observed that, although several factors can operate at the same time in influencing the wear process, in general wear is controlled by adhesion with contributions later on from corrosive and abrasive processes. The metallurgy of the liner also plays an important role in determining wear rates.     

Formal Techniques for Analysing Scenarios using Message Sequence Charts

This paper describes light-weight formal techniques based on Message Sequence Charts (MSCs) for capturing and validating early requirements and design. Our focus is on ease of use in specifying, simulating and validating scenarios, and checking their desired properties efficiently. We discuss how the formalism of High Level Message Sequence Charts (HMSCs or MSC'96), can be used to capture scenarios in use cases, thus enabling the use of tools for analysing them. We then present two formal semantics for HMSCs – an intuitive linear time semantics based on runs, and an operational semantics in terms of a labelled transition system. Next we present a way of describing desired properties of use case scenarios using templates, for validating scenarios with respect to informal requirements. The correctness properties of a collection of MSCs can then be established by efficient algorithms for finding paths in a directed graph representing the precedence relation on the events of the MSCs. We have implemented the operational semantics and the verification algorithms in the form of a simulation and verification tool for analysing scenarios.